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Full vulnerability report · 2025
CVE-2025-53809High confidence

Windows Local Security Authority Subsystem Service (LSASS) Denial of Service Vulnerability

Microsoft · Windows 11 Version 24H2

6.5MediumCVSS 3.1
Recommended action
Scheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Fix not verified
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2025-27321

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Fix not verified
01

What, why and how

Improper input validation in Windows Local Security Authority Subsystem Service (LSASS) allows an authorized attacker to deny service over a network.

What

Improper input validation in Windows Local Security Authority Subsystem Service (LSASS) allows an authorized attacker to deny service over a network.

Why

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

Improper input validation in Windows Local Security Authority Subsystem Service (LSASS) allows an authorized attacker to deny service over a network.

Why

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Improper Input Validation → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-20

CWE-20: Improper Input Validation. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkCWE-20
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-W-2025-2005Microsoft Windows und Windows Server: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in Microsoft Windows und Microsoft Windows Server ausnutzen, um seine Privilegien zu erhöhen, um Sicherheitsvorkehrungen zu umgehen, um Informationen offenzulegen, um beliebigen Programmcode auszuführen, und um einen Denial of Service Angriff durchzuführen.

Official advisory
CERT-FR · French · CERTFR-2025-AVI-0778Multiples vulnérabilités dans Microsoft Windows

embre 2025 Bulletin de sécurité Microsoft Windows CVE-2025-53801 du 09 septembre 2025 Bulletin de sécurité Microsoft Windows CVE-2025-53802 du 09 septembre 2025 Bulletin de sécurité Microsoft Windows CVE-2025-53803 du 09 septembre 2025 Bulletin de sécurité Microsoft Windows CVE-2025-53804 du 09 septembre 2025 Bulletin de sécurité Microsoft Windows CVE-2025-53805 du 09 septembre 2025 Bulletin de sécurité Microsoft Windows CVE-2025-53806 du 09 septembre 2025 Bulletin de sécurité Microsoft Windows CVE-2025-53807 du 09 septembre 2025 Bulletin de sécurité Microsoft Windows CVE-2025-53808 du 09 septembre 2025 Bulletin de sécurité Microsoft Windows CVE-2025-53809 du 09 septembre 2025 Bulletin de sécurité Microsoft Windows CVE-2025-53810 du 09 septembre 2025 Bulletin de sécurité Microsoft Windows CVE-2025-54091 du 09 septembre 2025 Bulletin de sécurité Microsoft Windows CVE-2025-54092 du 09 septembre 2025 Bulletin de sécurité Microsoft Windows CVE-2025-54093 du 09 septembre 2025 Bulletin de sécurité Microsoft Windows CVE-2025-54094 du 09 septembre 2025 Bulletin de sécurité Microsoft Windows CVE-2025-54095 du 09 septembre 2025 Bulletin de sécurité Microsoft Windows CVE-2025-54096 du 09 septembre 2025 Bulletin de sécurité Microsoft Windows CVE-2025-54097 du 09 septembre 2025 Bulletin de sécurité Microso

Official advisory
NCSC-NL · Dutch · NCSC-2025-0277Kwetsbaarheden verholpen in Microsoft Windows

Een kwaadwillende kan de kwetsbaarheden misbruiken om aanvallen uit te voeren die kunnen leiden tot de volgende categorieën schade: - Denial-of-Service (DoS) - Omzeilen van een beveiligingsmaatregel - Uitvoer van willekeurige code (root/adminrechten) - Uitvoer van willekeurige code (gebruikersrechten) - Toegang tot systeemgegevens - Toegang tot gevoelige gegevens - Verkrijgen van verhoogde rechten Van de kwetsbaarheid met kenmerk CVE-2025-55234 geeft Microsoft aan dat details publiek bekend zijn. Er is (nog) geen Proof-of-Concept-code (PoC) of exploit beschikbaar. De kwetsbaarheid bevindt zich in SMB en stelt een ongeauthenticeerde kwaadwillende in staat om zich de rechten van het slachtoffer toe te eigenen. Hiervoor moet de kwaadwillende het slachtoffer misleiden om acties uit te voeren, zoals het volgen van een link of openen van een bestand. ``` Capability Access Management Service (camsvc): |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-54108 | 7.00 | Verkrijgen van verhoogde rechten | |----------------|------|-------------------------------------| Windows BitLocker: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-54911 | 7.30 | Verkrijgen van verhoogde rechten | | CVE-2025-54912 | 7.80 | Verkrijgen van verhoogde rechten | |----------------|------|-------------------------------------| Windows Management Services: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-54103 | 7.40 | Verkrijgen van verhoogde rechten | |----------------|------|-------------------------------------| Windows Win32K - GRFX: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-54919 | 7.50 | Uitvoeren van willekeurige code | | CVE-2025-55228 | 7.80 | Uitvoeren van willekeurige code | | CVE-2025-55224 | 7.80 | Uitvoeren van willekeurige code | |----------------|------|-------------------------------------| Graphics Kernel: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-55223 | 7.00 | Verkrijgen van verhoogde rechten | | CVE-2025-55226 | 6.70 | Uitvoeren van willekeurige code | | CVE-2025-55236 | 7.30 | Uitvoeren van willekeurige code | |----------------|------|-------------------------------------| Windows NTLM: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-54918 | 8.80 | Verkrijgen van verhoogde rechten | |----------------|------|-------------------------------------| Windows Ancillary Function Driver for WinSock: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-54099 | 7.00 | Verkrijgen van verhoogde rechten | |----------------|------|-------------------------------------| Windows Kernel: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-54110 | 8.80 | Verkrijgen van verhoogde rechten | | CVE-2025-53803 | 5.50 | Toegang tot gevoelige gegevens | | CVE-2025-53804 | 5.50 | Toegang tot gevoelige gegevens | |----------------|------|-------------------------------------| Windows Bluetooth Service: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-53802 | 7.00 | Verkrijgen van verhoogde rechten | |----------------|------|-------------------------------------| Windows DWM: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-53801 | 7.80 | Verkrijgen van verhoogde rechten | |----------------|------|-------------------------------------| Microsoft Brokering File System: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-54105 | 7.00 | Verkrijgen van verhoogde rechten | |----------------|------|-------------------------------------| Windows Connected Devices Platform Service: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-54102 | 7.80 | Verkrijgen van verhoogde rechten | | CVE-2025-54114 | 7.00 | Denial-of-Service | |----------------|------|-------------------------------------| Microsoft Graphics Component: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-53800 | 7.80 | Verkrijgen van verhoogde rechten | | CVE-2025-53807 | 7.00 | Verkrijgen van verhoogde rechten | |----------------|------|-------------------------------------| Windows MultiPoint Services: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-54116 | 7.30 | Verkrijgen van verhoogde rechten | |----------------|------|-------------------------------------| Windows UI XAML Maps MapControlSettings: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-54913 | 7.80 | Verkrijgen van verhoogde rechten | |----------------|------|-------------------------------------| Windows Defender Firewall Service: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-53808 | 6.70 | Verkrijgen van verhoogde rechten | | CVE-2025-53810 | 6.70 | Verkrijgen van verhoogde rechten | | CVE-2025-54094 | 6.70 | Verkrijgen van verhoogde rechten | | CVE-2025-54104 | 6.70 | Verkrijgen van verhoogde rechten | | CVE-2025-54109 | 6.70 | Verkrijgen van verhoogde rechten | | CVE-2025-54915 | 6.70 | Verkrijgen van verhoogde rechten | |----------------|------|-------------------------------------| Windows Imaging Component: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-53799 | 5.50 | Toegang tot gevoelige gegevens | |----------------|------|-------------------------------------| Windows Routing and Remote Access Service (RRAS): |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-53797 | 6.50 | Toegang tot gevoelige gegevens | | CVE-2025-53798 | 6.50 | Toegang tot gevoelige gegevens | | CVE-2025-54095 | 6.50 | Toegang tot gevoelige gegevens | | CVE-2025-54096 | 6.50 | Toegang tot gevoelige gegevens | | CVE-2025-54097 | 6.50 | Toegang tot gevoelige gegevens | | CVE-2025-54106 | 8.80 | Uitvoeren van willekeurige code | | CVE-2025-55225 | 6.50 | Toegang tot gevoelige gegevens | | CVE-2025-53796 | 6.50 | Toegang tot gevoelige gegevens | | CVE-2025-53806 | 6.50 | Toegang tot gevoelige gegevens | | CVE-2025-54113 | 7.50 | Uitvoeren van willekeurige code | |----------------|------|-------------------------------------| Windows NTFS: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-54916 | 7.80 | Uitvoeren van willekeurige code | |----------------|------|-------------------------------------| Role: Windows Hyper-V: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-54091 | 7.80 | Verkrijgen van verhoogde rechten | | CVE-2025-54092 | 7.80 | Verkrijgen van verhoogde rechten | | CVE-2025-54098 | 7.80 | Verkrijgen van verhoogde rechten | | CVE-2025-54115 | 7.00 | Verkrijgen van verhoogde rechten | |----------------|------|-------------------------------------| Windows PowerShell: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-49734 | 7.00 | Verkrijgen van verhoogde rechten | |----------------|------|-------------------------------------| Microsoft Virtual Hard Drive: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-54112 | 7.00 | Verkrijgen van verhoogde rechten | |----------------|------|-------------------------------------| Windows MapUrlToZone: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-54107 | 4.30 | Omzeilen van beveiligingsmaatregel | | CVE-2025-54917 | 4.30 | Omzeilen van beveiligingsmaatregel | |----------------|------|-------------------------------------| Windows SMB: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-55234 | 8.80 | Verkrijgen van verhoogde rechten | |----------------|------|-------------------------------------| Windows SPNEGO Extended Negotiation: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-54895 | 7.80 | Verkrijgen van verhoogde rechten | |----------------|------|-------------------------------------| Windows Internet Information Services: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-53805 | 7.50 | Denial-of-Service | |----------------|------|-------------------------------------| Windows TCP/IP: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-54093 | 7.00 | Verkrijgen van verhoogde rechten | |----------------|------|-------------------------------------| Windows Local Security Authority Subsystem Service (LSASS): |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-54894 | 7.80 | Verkrijgen van verhoogde rechten | | CVE-2025-53809 | 6.50 | Denial-of-Service | |----------------|------|-------------------------------------| Windows SMBv3 Client: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-54101 | 4.80 | Uitvoeren van willekeurige code | |----------------|------|-------------------------------------| Windows UI XAML Phone DatePickerFlyout: |----------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |----------------|------|-------------------------------------| | CVE-2025-54111 | 7.80 | Verkrijgen van verhoogde rechten | |----------------|------|-------------------------------------| ```

Official advisory
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Fix not verified
Affected
10.0.26100.0 < 10.0.26100.6584
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 9 Sept 2025 · Last source change 20 Feb 2026, 16:00 UTC · CWE-20 · Improper Input Validation

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2025-27321
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceOther authority
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates →

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2025-53809 · cve.blacktree.nl